Re: [PATCH 1/2] Do not verify CFG if a function is discarded (PR

[Richard Biener <richard dot guenther at gmail dot com>]

On Tue, Mar 29, 2016 at 3:07 PM, Martin LiÅka <mliska@suse.cz> wrote:
> On 03/29/2016 02:10 PM, Richard Biener wrote:
>> On Tue, Mar 29, 2016 at 1:42 PM, Martin LiÅka <mliska@suse.cz> wrote:
>>> Hello.
>>>
>>> The problem with the original patch is that I'm forced to produce
>>> an empty BB to produce true/false edge needed for the 'index' check:
>>>
>>> /home/marxin/Programming/testhsa/run_tests/012-switch/switch-5.c:28:9: error: true/false edge after a non-GIMPLE_COND in bb 4
>>> /home/marxin/Programming/testhsa/run_tests/012-switch/switch-5.c:28:9: internal compiler error: verify_flow_info failed
>>> 0x93121a verify_flow_info()
>>>         ../../gcc/cfghooks.c:260
>>> 0xd5ae4e execute_function_todo
>>>         ../../gcc/passes.c:1971
>>> 0xd59ea6 do_per_function
>>>         ../../gcc/passes.c:1645
>>> 0xd5afc2 execute_todo
>>>         ../../gcc/passes.c:2011
>>>
>>> It would nicer to not produce empty block for that purpose, but the question
>>> is if the change is acceptable during the stage4?
>>
>> Hmm, why don't we short-cut things earlier in execute_one_pass where
>> we handle TODO_discard_function?
>> That is, sth like
>>
>> Index: gcc/passes.c
>> ===================================================================
>> --- gcc/passes.c        (revision 234453)
>> +++ gcc/passes.c        (working copy)
>> @@ -2334,6 +2334,33 @@ execute_one_pass (opt_pass *pass)
>>
>>    /* Do it!  */
>>    todo_after = pass->execute (cfun);
>> +
>> +  if (todo_after & TODO_discard_function)
>> +    {
>> +      pass_fini_dump_file (pass);
>> +
>> +      gcc_assert (cfun);
>> +      /* As cgraph_node::release_body expects release dominators info,
>> +        we have to release it.  */
>> +      if (dom_info_available_p (CDI_DOMINATORS))
>> +       free_dominance_info (CDI_DOMINATORS);
>> +
>> +      if (dom_info_available_p (CDI_POST_DOMINATORS))
>> +       free_dominance_info (CDI_POST_DOMINATORS);
>> +
>> +      tree fn = cfun->decl;
>> +      pop_cfun ();
>> +      gcc_assert (!cfun);
>> +      cgraph_node::get (fn)->release_body ();
>> +
>> +      current_pass = NULL;
>> +      redirect_edge_var_map_empty ();
>> +
>> +      ggc_collect ();
>> +
>> +      return true;
>> +    }
>> +
>>    do_per_function (clear_last_verified, NULL);
>>
>>    /* Stop timevar.  */
>> @@ -2373,23 +2400,6 @@ execute_one_pass (opt_pass *pass)
>>    current_pass = NULL;
>>    redirect_edge_var_map_empty ();
>>
>> -  if (todo_after & TODO_discard_function)
>> -    {
>> -      gcc_assert (cfun);
>> -      /* As cgraph_node::release_body expects release dominators info,
>> -        we have to release it.  */
>> -      if (dom_info_available_p (CDI_DOMINATORS))
>> -       free_dominance_info (CDI_DOMINATORS);
>> -
>> -      if (dom_info_available_p (CDI_POST_DOMINATORS))
>> -       free_dominance_info (CDI_POST_DOMINATORS);
>> -
>> -      tree fn = cfun->decl;
>> -      pop_cfun ();
>> -      gcc_assert (!cfun);
>> -      cgraph_node::get (fn)->release_body ();
>> -    }
>> -
>>    /* Signal this is a suitable GC collection point.  */
>>    if (!((todo_after | pass->todo_flags_finish) & TODO_do_not_ggc_collect))
>>      ggc_collect ();
>>
>>
>
> Hello Richi.
>
> Thanks for coming with the cleaner version of the patch.
> I've incorporated that patch and reg&bootstrap is running.
>
> Installable as soon as it finishes?

Yes.

Richard.

> Thanks,
> Martin
>
>>> Thanks,
>>> Martin
>